1. Field of the Invention
The present invention relates to an electronic endoscope system, particularly to a configuration for canceling a shift of processing timing of a video signal transmitted from an imaging device at the time of using electronic endoscopes different in length by connecting them.
2. Description of the Prior Art
An electronic endoscope system is configured by connecting various electronic endoscopes different in observation object to a processor unit for executing image processing. Because these electronic scopes are different in length (including cable length), the processor unit provides a delay time corresponding to the length of an electronic scope for a processing signal in order to adjust processing timing correspondingly to a transmission time of a video signal. Japanese Patent Application of Laid-Open Publication No. 03118023A discloses a conventional system for setting and controlling the delay time.
The system of this patent detects scope discriminating information and provides a delay time corresponding to a length of a previously-known electronic scope through tap selection of multitap delay in accordance with the information. In case of a custom electronic scope, a manual adjustment mechanism using a variable resistance is used so as to manually change delay times. As a result, it is possible to correspond to most electronic endoscopes different in length.